LOCAL DUALITY AND NONLEPTONIC B-DECAY

In the large N-c limit, the nonleptonic width of the B meson is determ ined by the lepton mass spectrum in semileptonic B decay and the hadro n mass spectrum in tau decay. This result can be compared with the non leptonic width computed using the operator product expansion and local duality, to estimate the violation of local duality in B decay. In th e absence of the required data, we use experimental Monte Carlo predic tions and find that the difference is small, at the few percent level. We estimate the theoretical uncertainty in our results from higher or der corrections (including 1/N-c effects). We also identify a new cont ribution to the Lambda(b) - B lifetime difference. (C) 1998 Published by Elsevier Science B.V. All rights reserved.